Data Compression using 2D Wavelet Analysis

(Type this code in editor then run it)

load woman;              % Load original image.

image(X)

title('Original Image')

colormap(map)

x = X(100:200,100:200);  % Select ROI

n = 5;                   % Decomposition Level

w = 'sym8';              % Near symmetric wavelet

[c l] = wavedec2(x,n,w); % Multilevel 2-D wavelet decomposition.

opt = 'gbl'; % Global threshold

thr = 20;    % Threshold

sorh = 'h';  % Hard thresholding

keepapp = 1; % Approximation coefficients cannot be thresholded

[xd,cxd,lxd,perf0,perfl2] = wdencmp(opt,c,l,w,n,thr,sorh,keepapp);

image(x)

title('Original Image')

colormap(map)

figure('Color','white'),image(xd)

title('Compressed Image - Global Threshold = 20')

colormap(map)

Output: